Method for improving the sensitivity of borax detection in toys

Abstract

The present application belongs to the technical field of borax detection, and particularly relates to a method for improving the detection sensitivity of borax in toys. In the process of detecting the borax content in toys by using alizarin S solution, diphenylcarbazone solution is added as a color developer. By observing the color of the solution after the reaction, it can be quickly screened whether the borax in the toy clay exceeds the limit value of 3750 mg / kg, whether the borax in the crystal mud gel exceeds the limit value of 1250 mg / kg, and the toy products with excessive borax content are screened out. The detection of the borax content in the crystal mud and the toy clay is realized, and the quantitative limits of 0, 1250 and 3750 mg / kg are achieved. The method of the present application can be used for on-site rapid detection, and the operation is simple, which provides convenience for on-site rapid screening and quantification of the borax content.

Description

Technical Field

[0001] This invention belongs to the field of borax detection technology, specifically relating to a method for improving the sensitivity of borax detection in toys. Background Technology

[0002] With societal progress and rising living standards, the types of children's toys have become more diverse, and consumers are paying greater attention to the safety of these toys. In recent years, toy clay, crystal slime gel, and foam glue have become increasingly popular among children due to their vibrant colors and excellent malleability.

[0003] However, in the production process of toy clay and crystal slime gel, most manufacturers add borax, which is harmful to the human body, in order to improve its performance. Borax can cause chronic poisoning after entering the human body, causing symptoms such as loss of appetite and indigestion. In addition, high doses of borax can even cause death.

[0004] It is evident that the detection and quantitative quality control of borax content in toy clay and crystal slime gel are of paramount importance.

[0005] Currently, the main methods for testing the borax content in toys such as clay and slime gel include inductively coupled plasma mass spectrometry, inductively coupled plasma spectroscopy, and ultraviolet spectrophotometry. These methods all require large-scale testing equipment to detect the presence of borax. If quantitative analysis of the boric acid content in the sample is required, complex calculations are also necessary. These methods are characterized by high testing costs, long processing reaction times, and low reproducibility and recovery rates.

[0006] For example, He Jianhua et al. mentioned in their study on rapid detection methods of borax in wheat flour, Grain Storage, 2015(5), that the method of using curcumin for color development and then using an ultraviolet spectrophotometer to measure the absorbance is used to detect the borax content in wheat flour. This technique requires the use of an ultraviolet spectrophotometer for measurement and then calculation to obtain the borax content, which is difficult to apply to rapid detection on site.

[0007] Furthermore, since the addition of borax to food is prohibited, the detection of borax in food only requires determining its presence, without the need for quantitative determination. However, there is no unified standard for the borax content in toys. The only EU toy directive, EN71-3 (2009 / 48 / EC), sets the limit for borax in super light clay at 1200 mg / kg. Moreover, there are no highly sensitive detection and quantitative methods on the market for the borax content in children's toys such as toy clay and crystal slime. Summary of the Invention

[0008] To address the aforementioned technical problems, this invention provides a method for improving the sensitivity of borax detection in toys.

[0009] This invention improves the traditional method for detecting borax by adding a diphenylcarbazone solution as a colorant during the detection of borax content in toys using alizarin S solution. The concentration of the diphenylcarbazone solution is 0.1–1.0 g / L, the concentration of the alizarin S solution is 0.1–0.5 g / L, and the volume ratio of the alizarin S solution to the diphenylcarbazone solution is 1:1–2. This operation significantly improves the sensitivity of borax detection. Compared with the detection results without the addition of diphenylcarbazone solution, the color change during borax detection is more significant after adding diphenylcarbazone solution.

[0010] The present invention provides a method for improving the detection sensitivity of borax in toys, which specifically includes the following steps:

[0011] Pretreatment of S1 test toys: Weigh 0.5-2.0g of the test toy directly, add the sample treatment solution, shake well, let stand, take the lower layer solution and filter it with a filter to obtain the clear liquid;

[0012] S2 Take the clear liquid after filtering S1, add alizarin red S solution, shake well, then add diphenylcarbazone solution, shake well and let stand;

[0013] S3 compares the color of the solution after standing in S2 with the standard colorimetric card to read the borax content, enabling the detection of the borax content in toys at the quantitative limits of 0 mg / kg, 1250 mg / kg, and 3750 mg / kg, and thus determining whether the borax content in the toys exceeds the standard.

[0014] The standard colorimetric card includes three colors: purple, orange-red, and orange-yellow. The borax content corresponding to purple is 0 mg / kg, the borax content corresponding to orange-red is 1250 mg / kg, and the borax content corresponding to orange-yellow is 3750 mg / kg.

[0015] Preferably, the toy is any one of toy clay, crystal slime, or foam glue.

[0016] In the method provided by this invention:

[0017] Preferably, the sample processing solution described in S1 contains at least one of Na2HPO4, NaH2PO4, and KH2PO4, and the concentration of the sample processing solution is 0.01 mol / L, and the pH is 7.2 to 7.4.

[0018] The inventors have discovered that the reaction is almost colorless under acidic conditions and the color is not obvious when the pH is too high, but it can produce good color in a lower pH range of 7.2 to 7.4. Therefore, in this invention, the pH of the sample treatment solution is selected to be 7.2 to 7.4.

[0019] Preferably, the filter in S1 is a needle filter, and its filter membrane material is aqueous polyethersulfone (PES), with a pore size of 0.45 μm.

[0020] Preferably, the concentration of the alizarin S solution in S2 is 0.2 g / L.

[0021] Preferably, the concentration of the diphenylcarbazone solution is 0.2 g / L.

[0022] Preferably, the volume ratio of alizarin S solution to diphenylcarbazone solution is 1:1.

[0023] Furthermore, the present invention provides a method for improving the detection sensitivity of borax in toys, comprising the following steps:

[0024] S1 Pretreatment of the toy sample to be tested: Take 0.5-2.0g of the toy sample to be tested, add 30-50mL of sample treatment solution, shake well, let stand for 5-10min, take the lower layer solution and filter it with a filter to obtain the clear liquid;

[0025] S2 Take the clear liquid after filtering S1, add 0.2 g / L alizarin red S solution, shake well, then add 0.2 g / L diphenylcarbazone solution, shake well and let stand. The volume ratio of the test clear liquid to alizarin red S solution to diphenylcarbazone solution is 10:1:1.

[0026] S3 compares the color of the solution after standing in S2 with the standard colorimetric card to read the borax content;

[0027] The standard colorimetric card includes three colors: purple, orange-red, and orange-yellow. The borax content corresponding to purple-red is 0 mg / kg, the borax content corresponding to orange-red is 1250 mg / kg, and the borax content corresponding to orange-yellow is 3750 mg / kg.

[0028] The beneficial effects of this invention are as follows:

[0029] (1) A method for improving the sensitivity of borax detection in toys is provided, namely, using an alizarin S solution with a concentration of 0.1 to 0.5 g / L to detect borax in toys, and adding dibenzarbazone solution as a colorant. The concentration of dibenzarbazone solution is 0.1 to 1.0 g / L, and the volume ratio of alizarin S solution to dibenzarbazone solution is 1:1 to 2. The addition of dibenzarbazone solution significantly improves the sensitivity of borax detection. After adding dibenzarbazone solution, the color signal of borax detection is significantly stronger than the detection signal intensity without the addition of dibenzarbazone solution.

[0030] (2) The method of the present invention enables the quantification of borax content in toys;

[0031] (3) The method of the present invention also provides a standard comparison system for the borax content of toys, that is, the borax content is presented in the form of a standard color chart. When testing borax, the borax content in the toy sample can be determined by comparing the color of the reaction. Specifically, when the borax content is 0 to 1250 mg / kg, it is orange-red; when the borax content is 1250 to 3750 mg / kg, it is orange-yellow; and when the borax content is 0, it is purple.

[0032] The method of this invention enables rapid on-site detection and quantification of borax, quickly screening whether borax in toy clay exceeds the limit of 3750 mg / kg and whether borax in crystal slime gel exceeds the limit of 1250 mg / kg, and screening out toy products with excessive borax content, thus facilitating rapid on-site screening. Attached Figure Description

[0033] Figure 1 This is a color chart showing the detection of borax content at different concentrations in Example 1 of the present invention;

[0034] Figure 2 This is a color chart corresponding to the transition concentrations in the borax content detection process of Example 1 of the present invention;

[0035] Figure 3 This is a color chart of a colorimetric card for rapid quantitative determination of borax content in this invention;

[0036] Among them, a is purplish-red, corresponding to a borax content of 0 mg / kg; b is orange-red, corresponding to a borax content of 1250 mg / kg; and c is orange-yellow, corresponding to a borax content of 3750 mg / kg.

[0037] Figure 4 This is a graph showing the results of detecting borax content in different ultralight clay samples in Example 2 of the present invention;

[0038] Figure 5 This is a graph showing the results of detecting the borax content in different crystal mud samples in Example 3 of the present invention;

[0039] Figure 6 This is a color graph showing the detection of borax content at different concentrations in Comparative Example 1 of the present invention when no diphenylcarbazone solution was added. Detailed Implementation

[0040] To enable those skilled in the art to better understand the present invention, the present invention will now be further described in conjunction with specific embodiments.

[0041] Example 1

[0042] Borax standards of different concentrations were prepared using a phosphate buffer solution with a pH of 7.2. The concentrations were 50, 100, 250, 300, 500, 1000, 1200, 1250, 1500, 2500, 3750, and 5000 mg / kg. 10 mL of each solution was taken and 1 mL of 0.2 g / L Alizarin Red S solution was added. The mixture was shaken well and then 1 mL of 0.2 g / L Diphenylcarbazone solution was added. The mixture was shaken well and allowed to stand for 30 seconds.

[0043] The color development of borax standard solutions of different concentrations is shown in the attached figure. Figure 1 As shown, attached Figure 1 From left to right, the concentrations of the borax standard solutions gradually increase.

[0044] It is evident that as the concentration of borax standard increases, the color of the detection signal exhibits a very significant change from dark purple to light purple, then to orange-red and orange-yellow. This is particularly noticeable when the concentration of borax standard is 1250 mg / kg and 3750 mg / kg, showing a clear color inflection point, as shown in the attached figure. Figure 2 As shown.

[0045] Therefore, in order to better quantify the borax content in toys, a colorimetric card was established with 0 mg / kg, 1250 mg / kg, and 3750 mg / kg as standard values. The color settings of the colorimetric card are shown in the attached figure. Figure 3 As shown.

[0046] Example 2

[0047] Three samples of ultralight clay were purchased from different stores in the market. 1g of each sample was taken using tweezers and added to 50mL of 0.01mol / L phosphate buffer solution (pH 7.2). The mixture was shaken well and allowed to stand for 5 minutes. The lower layer of the solution was then filtered. 10mL of the filtered clear liquid was taken and 1mL of 0.2g / L Alizarin Red S solution was added. After shaking well, 1mL of 0.2g / L diphenylcarbazine solution was added, shaken well, and allowed to stand for 30 seconds. A control was used, with the sample without diphenylcarbazine solution. The test results are shown in the appendix. Figure 4 .

[0048] Among them, the appendix Figure 4 The upper colorimetric tube shows the color development in the control without the addition of diphenylcarbazone solution, while the lower colorimetric tube shows the color development of borax detection in clay after the addition of diphenylcarbazone solution.

[0049] From the appendix Figure 4 It can be seen that after adding diphenylcarbazone solution during the detection of borax, the color intensity is deeper and the difference between colors is more significant.

[0050] In addition, the results of testing three clay samples showed that the borax content in ultra-light clay toys on the market varied and the differences were quite significant, but the content was all below 3750 mg / kg.

[0051] Example 3

[0052] Purchase three portions of crystal mud from different shops in the market. Take 1g of each portion with tweezers, add 50mL of phosphate buffer solution, shake well, and let stand for 5 minutes. Take the lower layer of solution and filter it. Take 10mL of the filtered clear liquid, add 1mL of 0.1g / L alizarin red S solution, shake well, add 1mL of 0.5g / L diphenylcarbazone solution, shake well, and let stand for 30 seconds.

[0053] If the solution color changes from purplish-red to pink, or from purplish-red to orange-yellow, it indicates that the ultralight clay contains borax. Then, compare it with the color chart to determine whether the borax content in the clay exceeds the standard or limit. If the solution color is orange-yellow, the borax content in the clay is higher than 3750 mg / kg; if the solution color is orange-red, the borax content in the clay is between 1250 mg / kg and 3750 mg / kg.

[0054] The test results for borax content in this embodiment are shown in the appendix. Figure 5 .

[0055] Among them, the appendix Figure 5 The upper colorimetric tube shows the color development in the control without the addition of diphenylcarbazone solution, while the lower colorimetric tube shows the color development of borax detection in clay after the addition of diphenylcarbazone solution.

[0056] Appendix Figure 5 The results showed that adding diphenylcarbazone solution to borax detection significantly improved the sensitivity of borax detection. Furthermore, the borax content in crystal mud was generally much higher than that in clay, with two out of the three crystal mud samples having a borax content higher than 2700 mg / kg.

[0057] Comparative Example 1

[0058] Unlike Example 1, no diphenylcarbazone solution was added in this comparative example, but all other operations were the same as in Example 1.

[0059] The colors of the solutions after the reaction in different samples are shown in the attached figure. Figure 6 As shown, attached Figure 6 From left to right, the concentration of borax gradually increases.

[0060] Comparison Appendix Figure 6As shown in the test results of Example 1, the color intensity of the solution after the reaction is far less than that of the solution with added diphenylcarbazin solution when no diphenylcarbazin solution is added. Furthermore, the color difference obtained without adding diphenylcarbazin solution is not obvious at different concentrations, making it even more difficult to distinguish and quantify the borax content. It is evident that the addition of diphenylcarbazin solution significantly improves the accuracy and sensitivity of borax detection.

[0061] Therefore, the method of the present invention can achieve rapid detection and quantification of borax content in ultra-light clay samples, crystal slime and other toys. This is beneficial for manufacturers to quickly test whether the borax content in their products is up to standard before they leave the factory. At the same time, after purchasing clay toys, consumers can also quickly quantify the borax content. For clay, crystal slime and other toys with high borax content, treatment can be carried out to avoid unnecessary harm to users or players.

Claims

1. A method for improving the sensitivity of borax detection in toys, characterized in that, during the detection of borax content in toys using alizarin S solution, A diphenylcarbazin solution was added as a colorant, with a concentration of 0.1~1.0 g / L and a concentration of 0.1~0.5 g / L for alizarin S solution. The volume ratio of alizarin S solution to diphenylcarbazin solution was 1:1~2.

2. The method for improving the detection sensitivity of borax in toys as described in claim 1, characterized in that, The toy is any one of toy clay, crystal slime, or foam glue.

3. The method for improving the detection sensitivity of borax in toys as described in claim 1, characterized in that, Specifically, the steps include the following: Pretreatment of S1 toy sample: Weigh 0.5~2.0 g of the toy sample, add the sample treatment solution, shake well, let stand, take the lower layer solution and filter it with a filter to obtain the clear liquid; S2 Take the clear liquid after filtering S1, add alizarin red S solution, shake well, then add diphenylcarbazone solution, shake well and let stand; S3 compares the color of the solution after standing in S2 with the standard colorimetric card to read the borax content, enabling the detection of the borax content in toys at the quantitative limits of 0 mg / kg, 1250 mg / kg, and 3750 mg / kg, and thus determining whether the borax content in the toys exceeds the standard. The standard colorimetric card includes three colors: purple, orange-red, and orange-yellow. Purple corresponds to a borax content of 0 mg / kg, orange-red corresponds to a borax content of 0~1250 mg / kg, and orange-yellow corresponds to a borax content of 1250~3750 mg / kg.

4. The method for improving the detection sensitivity of borax in toys as described in claim 3, characterized in that, The sample processing solution described in S1 contains at least one of Na2HPO4, NaH2PO4, and KH2PO4, and the concentration of the sample processing solution is 0.01 mol / L, and the pH is 7.2~7.

4.

5. The method for improving the detection sensitivity of borax in toys as described in claim 3, characterized in that, The filter in S1 is a needle filter with a water-based polyethersulfone membrane and a pore size of 0.45 μm.

6. The method for improving the detection sensitivity of borax in toys as described in claim 1, characterized in that, The steps include the following: S1 Pretreatment of the toy sample to be tested: Take 0.5~2.0 g of the toy sample to be tested, add 30~50 mL of sample treatment solution, shake well, let stand for 5~10 min, take the lower layer solution and filter it with a filter to obtain the clear liquid; S2 Take the clear liquid after filtering S1, add 0.2 g / L alizarin red S solution, shake well, then add 0.2 g / L diphenylcarbazone solution, shake well and let stand. The volume ratio of the test clear liquid to alizarin red S solution to diphenylcarbazone solution is 10:1:

1. S3 compares the color of the solution after standing in S2 with the standard colorimetric card to read the borax content; The standard colorimetric card includes three colors: purple, orange-red, and orange-yellow. The borax content corresponding to purple is 0 mg / kg, the borax content corresponding to orange-red is 1250 mg / kg, and the borax content corresponding to orange-yellow is 3750 mg / kg.

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